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Intel Haswell Linux Virtualization: KVM vs. Xen vs. VirtualBox

The latest chapter to our lengthy Intel Haswell on Linux saga is virtualization benchmarks. From Fedora 19 with the very latest software components for Linux virtualization, the performance of KVM, Xen, and VirtualBox were benchmarked from the Intel Core i7 4770K "Haswell" CPU.

Odd to see Virtual Box falling behind and crashing, usually it is pretty reliable. I hope it had the guest drivers installed. Could be due to Haswell and the CPU going into a sleep state or something as reported with earlier Haswell issues? Also I wonder if performance is impacted by the default Virtual box file system settings. VB by default uses a dynamically expanding file system on the host fs, that enables snapshots etc whereas others by default use an exactly sized image file which doesn't handle snapshots (or sometimes the host LVM, which avoids the "filesystem on filesystem" double layer)

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The latest chapter to our lengthy Intel Haswell on Linux saga is virtualization benchmarks. From Fedora 19 with the very latest software components for Linux virtualization, the performance of KVM, Xen, and VirtualBox were benchmarked from the Intel Core i7 4770K "Haswell" CPU.

Note to all: remember he doesn't mess with the knobs (heh). Only tests with default settings. So, for these benchmarks, KVM and Xen seemed to be better out of the box than the VB, though I don't know that I've ever seen computational benchmarks where VB beats either of the other two. KVM, for one, could have enabled the host cpu settings for advanced instructions instead of being stuck with sse2 (IIRC), and that should've sped up some of the benchmarks.

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Note to all: remember he doesn't mess with the knobs (heh). Only tests with default settings. So, for these benchmarks, KVM and Xen seemed to be better out of the box than the VB, though I don't know that I've ever seen computational benchmarks where VB beats either of the other two. KVM, for one, could have enabled the host cpu settings for advanced instructions instead of being stuck with sse2 (IIRC), and that should've sped up some of the benchmarks.

Its also important to note that "K-Series" Intel CPU's don't support the virtualization extensions anymore so these tests are being done at a nice big performance penalty regardless of anything done wrong in Michael's software configuration.

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Its also important to note that "K-Series" Intel CPU's don't support the virtualization extensions anymore so these tests are being done at a nice big performance penalty regardless of anything done wrong in Michael's software configuration.

It has VT-X but not VT-D. So virtualized performance should still be fine, you just can't directly access PCI devices etc.

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Xen and KVM are bare metal hypervisors, where virtual box is a hosted hypervisor. Doing your virtualization at application level is always going to be slower than at kernel level unless somethings really wrong.